Portable blowers and portable convertible blower/vacuums (blower/vacs) are in common use by homeowners and professionals for the removal of debris from yards, driveways, and sidewalks. A convertible blower/vac is a device which can be used as a blower or can be converted to operate as a vacuum. While the present invention can be applied to either a blower or a blower/vac, it would apply to the latter only when used in the blower mode.
A typical blower or blowerdvac comprises a housing having a motor operatively connected to an internal, rotating impeller. In blower operation, a sweeping action is created by the production of a fast moving stream of air generated by the rotating impeller. The impeller draws air into the housing through an air inlet. An air inlet cover permits air to enter the housing while at the same time preventing the entrance of foreign objects and debris. An air outlet on the housing directs the air stream to a removable blower or extension tube. The extension tube has an upstream end that connects to the air outlet and a downstream end through which air exits. Typically, the cross-sectional area of the downstream end is less than that of the upstream end. This causes an air stream of higher velocity and pressure at the downstream end, permitting greater precision and force in blowing debris.
Frequently, an air concentrator nozzle is provided that attaches to the downstream end of the extension tube to further reduce the cross-sectional area and, thus, further increase the air stream velocity and pressure. One preferred feature of the air concentrator nozzle is its ability to be easily attached and detached from the extension tube. If connection/removal of the nozzle is difficult or time consuming, operators are less likely to install the nozzle or to remove it once it is installed. By simplifying this procedure, the blower is thereby perceived to be more versatile.
Another desirable feature is that, once attached, the air concentrator nozzle should be positively secured to the extension tube. During use, the downstream end of the tube and the nozzle are often jarred by contact with the ground. Repeated impact of this nature may loosen the nozzle, resulting in air leaks around the nozzle/extension tube interface and perhaps even separation of the nozzle from the tube. To require the operator to frequently re-seat or re-attach the nozzle during use is inconvenient. Thus, securely retaining the nozzle is advantageous.
Cost is also a constant concern with portable blowers and blower/vacs. Accordingly, a nozzle that addresses the issues listed herein must also be economical to produce. Manufacturing complexity, excessive weight and extraneous parts adversely affect blower cost. For this reason, a nozzle that is simple to produce and requires no additional components for attachment is highly desirable.
Many types of blowers utilizing air concentrator nozzles are known. While these nozzles address the primary concern of decreasing the effective cross-sectional area of the extension tube, unresolved issues remain.
For example, U.S. Pat. No. Des. 357,774 issued to Kishi on Apr. 25, 1995 and assigned to Japanic Corp., discloses a concentrator nozzle that appears to attach to the downstream end of the extension tube by a friction fit.
U.S. Pat. No. Des. 297,274 issued to Komiya et al. on Aug. 16, 1988 and assigned to Fuji Robin, discloses a concentrator nozzle that attaches to the downstream end of the extension tube with a clamp-like device (see FIG. 4).
U.S. Pat. No. 5,652,995 issued to Henke et al. and assigned to WCI Outdoor Products, Inc., discloses a nozzle "which has threads . . . at the upstream end of the nozzle . . . for connecting the nozzle to a blower tube." Column 2, lines 2-3.
U.S. Pat. No. 2,586,145 issued to Breuer et al. on Feb. 19, 1952 and assigned to Breuer Electric Manf. Co., discloses a nozzle that attaches to the blower tube by way of a bayonet mount.
U.S. Pat. Nos. 4,553,284 issued to Strumbos on Nov. 19, 1985 and No. 2,068,496 issued to Linghammar and assigned to Electrolux Corp., disclose nozzles for use with vacuum cleaners. In both inventions, the nozzle forms a female receptacle into which the suction tube from the vacuum is then placed.
U.S. Pat. No. 4,746,274 issued to Kiyooka et al. and assigned to 501 Komatsu Zenoah Co., discloses in FIG. 9 an alternative embodiment utilizing a storable blower pipe. The disclosure states that "[t]o use the blower pipe 153, it is pulled out of the storage chamber 150, and the conical surfaces 152 and 154 are engaged tightly with each other." Column 6, lines 25-28.
Finally, U.S. Pat. No. 3,938,218 issued to DeAmicis on Feb. 17, 1976, discloses a pressurized cleaning tool with a telescoping inner tube.
Thus, there are several nozzles know in the art. The present invention pertains to a blower with a novel air concentrator nozzle.